Evolution of INPOP planetary ephemerides and Bepi-Colombo simulations

Abstract

We give here a detailed description of the latest INPOP planetary ephemerides IN-POP20a. We test the sensitivity of the Sun oblateness determination obtained with INPOP to different models for the Sun core rotation. We also present new evaluations of possible GRT violations with the PPN parameters β,γ and μ/µ. With a new method for selecting acceptable alternative ephemerides we provide conservative limits of about 7.16×10 −5 and 7.49×10 −5 for β−1 and γ − 1 respectively using the present day planetary data samples. We also present simulations of Bepi-Colombo range tracking data and their impact on planetary ephemeris construction. We show that the use of future BC range observations should improve these estimates, in particular γ. Finally, interesting perspectives for the detection of the Sun core rotation seem to be reachable thanks to the BC mission and its accurate range measurements in the GRT frame.

INPOP Planetary ephemerides and applications in the frame of the BepiColombo mission including new constraints on the graviton mass and dilaton parameters

“…Two important changes have also been brought to the dynamical modeling : first the introduction of the Lense-Thirring acceleration and second, a more realistic modeling of the accelerations induced by the Trans-Neptunian objects on the outer solar system. A full description of the INPOP20a modele and fit can be found in [15,14]. INPOP21a [14] and INPOP22a are two updates of INPOP20a with more Juno and MEX data.…”

“…This very fast rotating core was suggested to explain a recent, but still debated, claim of g-mode detection. The way we derive the amplitude of Sun angular momentum S from the Sun core rotation is explained in [15] and derived from the following equation :…”

“…This is the reason why a direct adjustment of these three parameters together in a global fit leads to highly correlated determinations and under-estimated uncertainties. The detailed method of the Monte Carlo simulations for building the Weighted Residual Sum of Squares distribution is explained in [15]. It is based on the study of the instrumental noise variability of the INPOP adjustment and its impact on the WRSS estimation following the equation…”